TM 5-4320-302-14
6-18. CRANKSHAFT ASSEMBLY (CONT)
Location/Item
Action
Remarks
c.
However, if the crankpins are evenly worn,
not out-of-round, and the crankshaft journal
diameters are within specified limits, the con-
dition may be rectified by replacing con-
necting rod big-end bearings. Replace the
big-end bearings in accordance with paragraph
6-17. Check the big-end bearing radial clear-
ance. If it exceeds the tolerance limits of
0.0020 to 0.0118 inch (0.05 to 0.3 mm), the
crankshaft must be replaced.
d.
If the measurements at points 1 and 2 differ
by more than 0.0028 inch (0.07 mm) and/or
one set is outside the tolerance limits, the
crankpin is worn into a conical shape and the
crankshaft must be replaced. If the measure-
ments along axis A and B differ by more than
0.0028 inch (0.07 mm) and/or one set is out-
side the tolerance limits, the crankpin is worn
into an oval shape and the crankshaft must be
replaced. For both these out-of-round condi-
tions, also check connecting rods, pistons, and
cylinders for unusual wear.
e.
The crankpin width at point 3 should be
1.3386 to 1.3401 inches (34.0 to 34.039 mm).
The fillet radius measurement should be 0.1693
to 0.1772 inch (4.30 to 4.50 mm). If either
measurement is outside the specified limits, the
crankshaft must be replaced.
9.
Replacement
If the crankshaft must be replaced, the following
crankshaft
crankpin diameter normal and undersizes are
crankpins
available:
6-145
